Log feeding mechanism



1966 KARL-ERIK A. JONSSON ET AL 3,228,439

LOG FEEDING MECHANISM Filed Nov. 26, 1963 3 Sheets-Sheet 1 Jan. 11, 1966 KARL-ERIK A. JONSSON ETAL 3,228,439

1106 FEEDING MECHANISM Filed Nov. 26, 1963 2 Sheets-Sheet 2 Fig. 3

United States Patent 3,228,439 LOG FEEDING MECHANISM Karl-Erik Arnold Jonsson, Gavle, and Nils Olof Iohansson, Vallingby, Sweden, assignors to Soderhamns Verkstader AB, Soderhamn, Sweden, a corporation of Sweden Filed Nov. 26, 1963, Ser. No. 326,111

Claims priority, applicationrgweden, Dec. 21, 1962,

3 8 3 Claims. (01. 144-208) The invention relates to a log feeding mechanism, especially useful for feeding logs through debarking machines of the hollow-rotor type.

To feed logs through debarking rotors it is customary to place feeding mechanisms before as well as after the debarking rotor. Such a feeding mechanism may comprise a set of two or three driv'en rolls movable towards and from each other to engage the envelope surface of a log in a common plane perpendicular to the longitudinal direction of the log. A log supported in this way by a single set of feed rolls only will, however, often be subjected to a swinging motion before its fore end is introduced into the rotor or after its rear end has left the rotor, and particularly this is the case when the log is rather short. It is true that it is known to place a separate centering device between the feeding mechanism and the debarking rotor, but such a device is bulky and involves no satisfactory solution. Above all, the device is not useful in feeding short logs. It has also been proposed to dispose the feed rolls close to the debarking rotor, but the oscillations of the logs are only reduced to some extent in this way.

The object of the invention is to provide an improved feeding mechanism by which said inconvenience is eliminated so that a good guidance of the logs is obtained. For that purpose, an auxiliary roll having an essentially smaller diameter than the feed rolls is rotatably mounted in parallel with and close to the periphery of each feed roll in such a way that the auxiliary rolls are in engagement with the surface of a log located between the feed rolls. In other words, the peripheral surface portions of each feed roll and its auxiliary roll facing the centre line of the rotor are located in a common tangent plane parallel to said centre line, i.e. to the direction of feed. In this way, a log fed into the debarking rotor will always be supported at two spaced peripheral lines so that any risk of oscillation is eliminated when the debarking tools engage the end of a log introduced into the rotor.

The auxiliarly rolls may be journalled freely rotatable but are preferably driven and in that case they must of course have the same peripheral speed as the feed rolls. Preferably each feed roll and its auxiliary roll are mounted on a common support.

The invention is described in detail with reference to the accompanying drawings, in which FIGURE 1 shows a diagrammatic view of two feed mechanisms disposed before and after a debarking rotor, respectively;

FIGURE 2 shows the device as seen from the right in FIG. 1;

FIGURE 3 shows, on a larger scale, an axial section through a feed roll and its connection to an auxiliary roll;

FIGURE 4 shows a cross section on the line IVIV in FIG. 3.

FIGURE 1 shows a preferred location of the feed mechanisms in relation to the debarking machine. An auxiliary roll 5 is disposed between each feed roll 6 and the inlet end of the debarking rotor 7, and at the discharge end of the rotor auxiliary rolls 5' are disposed immediately after the feed rolls 6, as seen in the direction of feed.

3,228,439 Patented Jan. 11, 1966 It is also apparent from FIG. 1 that those surface portions of each feed roll and cooperating auxiliary roll which face the rotor axis and are adapted to engage a log are located in a common plane parallel to the direction of feed.

FIGURE 2 shows a triangulated arrangement of rolls comprising three feed rolls 6 disposed symmetrically around the axis of the rotor. The shafts (not shown) of the rolls are journalled in pivotable casings 8 encasing also the required driving transmissions, as shown in FIG. 15 of the US. Patent 2,857,945, for instance. The casings 8 are interconnected by means of a system of levers and links 9, 10 in such a way that the feed rolls are swung simultaneously through equally great angles to and from the centre line of the rotor. The auxiliary rolls 5 have their shafts journalled in sleeves 11 supported by the easings 8. In the embodiment shown, all rolls carry spikes, but instead of it they may also be knurled or fluted, as known per se.

As seen in FIG. 3, the feed roll 6 may be composed of a number of different parts which need not be described in detail. The only thing of interest in this connection is that the roll shaft 13 journalled in the casing 8 carries a funnel-shaped member 14 splined thereto and secured by means of screws 15 to the inner end of the roll. Inside of the roll this member 14 is provided with a gear rim 16. A supporting ring 17 mounted on the outer end of the casing 8 is screwed to an annular cap 18 which encloses the gear rim 16. The cap 18 has a radially extended portion 19 (see FIG. 4) made integral with the sleeve 11 in which the auxiliary roll 5 is journalled. The journalled end of the auxiliary roll is provided with a gear rim 22 between two ball bearings 20, 21 in front of a lateral opening in the sleeve 11, and a gear Wheel 23 engaging the two gear rims 16 and 22 has a shaft 24 which is journalled in the cap 18. Thus, the auxiliary roll 5 is driven from the shaft 13 of the feed roll 6 by this transmission and owing to the intermediate wheel 23 both rolls 5, 6 will rotate in the same direction. Moreover, the transmission is designed such that the same peripheral speed is imparted to both rolls 5, 6.

It is of advantage that the diameter of the auxiliary roll 5 is less than A of that of the feed roll (the spikes included in both cases). Further, the auxiliary roll should be located as closely to the feed roll as possible so as not to impede the disposal of the feed roll immediately before the infeed end of the debarking rotor (see FIG. 1). It is preferable that the periphery of the auxiliary roll be located inside a square circumscribing the cross section of the feed roll, as shown in FIG. 4. Such an arrangement is facilitated, if the peripheral rows of spikes of the two rolls are placed in zig-zag in relation to each other, as shown in FIG. 3, so that the spikes of the auxiliary roll extend into the spaces between the rows of spikes of the feed roll and vice versa. However, if desired, as clearly shown in FIG. 1, the auxiliary roll 5 may be disposed with the longitudinal axis thereof located inside a square circumscribing the cross section of the feed roll 6 but with a portion of the periphery of the auxiliary roll 5 located outside of such square.

The invention is not limited to the construction shown and described above. For instance, auxiliary rolls may be of advantage also in feed mechanisms comprising two or four cooperating feed rolls. Further, the gear wheel transmission described may be replaced by a belt transmission, and in such case the intermediate wheel 23 can be dispensed with.

What we claim is:

1. A log feeding mechanism comprising at least two cooperating driven feed rolls movable toward and away from each other to engage the external surface of a log in a common plane perpendicular to the longitudinal axis of the log, a support for each roll, a drive shaft journalled on each support and fixed to each roll, an auxiliary shaft journalled on each support and disposed parallel to said drive shaft, means for driving said auxiliary shaft from said drive shaft, and an auxiliary roll mounted on each auxiliary shaft, each auxiliary roll being of an essential ly smaller diameter than each feed roll, each auxiliary roll being disposed parallel With and close to the periphery of the adjacent feed roll in such a Way that the auxiliary rolls are in engagement with the surface of a log located between the feed rolls.

2. A log feeding mechanism as defined in claim 1 in which the axis of each auxiliary roll is located inside a square ci-rcumscribing the cross section of the adjacent feed roll.

References Cited by the Examiner UNITED STATES PATENTS 2,785,715 3/1957 Brundell et a1 7 144-247 2,857,945 10/1958 Brundell et 211. 2,958,350 11/1960 Peyton.

WILLIAM W. DYER JR., Primary Examiner. 

1. A LOG FEEDING MECHANISM COMPRISING AT LEAST TWO COOPERATING DRIVEN FEED ROLLS MOVABLE TOWARD AND AWAY FROM EACH OTHER TO ENGAGE THE EXTERNAL SURFACE OF A LOG IN A COMMON PLANE PERPENDICULAR TO THE LONGITUDINAL AXIS OF THE LOG, A SUPPORT FOR EACH ROLL, A DRIVE SHAFT JOURNALLED ON EACH SUPPORT AND FIXED TO EACH ROLL, AN AUXILIARY SHAFT JOURNALLED ON EACH SUPPORT AND DISPOSED PARALLEL TO SAID DRIVE SHAFT, MEANS FOR DRIVING SAID AUXILIARY SHAFT FROM SAID DRIVE SHAFT, AND AN AUXILIARY ROLL MOUNTED ON EACH AUXILIARY SHAFT, EACH AUXILIARY ROLL BEING OF AN ESSENTIALLY SMALLER DIAMETER THAN EACH FEED ROLL, EACH AUXILIARY ROLL BEING DISPOSED PARALLEL WITH AND CLOSE TO THE PERIPHERY OF THE ADJACENT FEED ROLL IN SUCH A WAY THAT THE AUXILIARY ROLLS ARE IN ENGAGEMENT WITH THE SURFACE OF A LOG LOCATED BETWEEN THE FEED ROLLS. 